Even the Al Jazeera article you linked to notes that it is a bit more complicated than that.

The Egyptians claim that they are terminating the agreement because Israel has not paid.

Israel claims this is unfair because Egypt failed to supply the gas that Israel already paid for...

If you use google and learn even more, it seems that Egypt is under pressure to end their relations with Israel and that the pipeline has been blown up by Arab terrorists several times. As a result, Egypt failed to supply the gas to Israel in the first place and is now using the excuse that Israel has not been paying the monthly bill for 4 months (which makes sense when the gas has not been delivered to Israel for many more months).